I am following Dr J’s reading plan from the Western Tradition. It is a 7 year plan to read the entire Great Books of the Western World and Gateway to the Great Books. Unfortunately it seems to have been abandoned part way through, though he does seem to take extended breaks at times and return so there’s hope! Failing that, I would hope that if I ever make it to where he got up to, I might be in a better position to continue on my own…

Each volume of the Gateway to the Great Books contains many snippets of other works, whereas the ‘actual’ Great Books tends to contain complete works. Therefore , it is unfeasible at this time to try and collect these too (though I have bought a couple of books containing some of the writing).
If the goal was to read them all (which is should be!) most, if not at all writings can be found online.